Nematode Communities in Soils of the Same Volcanic Origin across a Gradient of Naturalization: From Intensive Agriculture to Forest

Nematodes play a key role in ecological environments. Biotic indices based on soil nematode community are effectively used for assessing soil health status. This work represents the opportunity to investigate three different management practices continuously maintained for 40 or more decades on soils with the same geological origin. This unique feature allows us to reduce variables and link biotic with abiotic factors. Therefore, the nematode communities of three neighboring volcanic soils under different managements were examined. The maximum values in soil biodiversity were found in the forest environment in which all the trophic groups were detected and well balanced. Instead, in permanent grassing and carnation crop greenhouse (CG), biodiversity indices progressively decreased with the intensification of agricultural practices. Furthermore, CG showed a stronger dominance of a specific plant-parasitic nematode identified as Heterodera daverti. Nematode indicators demonstrated that changes in the nematode community gradually varied from anthropic to natural environments whereas soil properties were feebly correlated to nematode community indicators. In conclusion, we demonstrated that biodiversity and ecological indices applied to the soil nematode community are effective at detecting alterations due to anthropogenic impact. Nematodes seem to be susceptible to perceiving the soil dynamics

The vertical and horizontal distribution of Mesocriconema xenoplax (Raski, 1952) in Trentino vineyards (Northern Italy)

Spatial distribution of Mesocriconema xenoplax (Raski, 1952) was investigated in vineyards in the Trentino region (Northern Italy). Horizontal distribution showed characteristic aggregate pattern for nematodes, correlated to the symptomatology of the localized spots of infestations. The vertical distribution, in compact texture soils, revealed maximum population levels of the nematode in the top layers depending on the root occurrence that, in such conditions, is lower at the deeper levels. Higher nematode number was found at greater depths in loose soils, where roots easier penetrate. The knowledge gained from the spatial distribution of this species is fundamental to investigate the effectiveness of different sampling patterns in order to improve efficacy of control strategies

MANAGEMENT OF THE ROOT-KNOT NEMATODE MELOIDOGYNE INCOGNITAON TOMATO WITH DIFFERENT COMBINATIONS OF NEMATICIDESAND A RESISTANT ROOTSTOCK: PRELIMINARY DATA

In south Italy, tomato growers commonly face severe root-knot nematode infestations. Alternative methods ofcontrol are required because of the high toxicity of current pesticides. Therefore, the potential of an integrated pestmanagement strategy for the control of root-knot nematodes on tomato in greenhouse was investigated. The nematodesusceptible tomato cv. Ikram, non-grafted or grafted onto the tomato rootstock cv. Armstrong, with intermediate resistanceto the nematode, in combination with soil applications of the nematicides fosthiazate, oxamyl, and abamectin were tested.The resistant rootstock significantly reduced nematode soil population levels and root galling index until one month aftertransplanting, when soil temperature was below 28°C, but not by harvest due to increased soil temperature. Fosthiazate,abamectin and oxamyl increased tomato yield and reduced root galling caused by Meloidogyne incognita. The synergisticeffect of the rootstock resistant to root-knot nematodes and soil treatments of fosthiazate in combination with abamectin oroxamyl could successfully be employed in integrated pest management programs to control M. incognita in tomato

Interactions between nematodes and fungi: a concise review

A short review of the complex interactions is reported between nematodes and fungi, which are not always clear because of the rhizosphere complexity and inadequate techniques of investigation

Sensory Adaptation of Antennae and Sex Pheromone-Mediated Flight Behavior in Male Oriental Fruit Moths (Leptidoptera: Tortricidae) After Prolonged Exposure to Single and Tertiary Blends of Synthetic Sex Pheromone

Sensory adaptation has been measured in the antennae of male Grapholita molesta (Busck) after 15 min of exposure to its main pheromone compound (Z)-8-dodecen-1-yl acetate (Z8-12:OAc) at the aerial concentration of 1 ng/m(3) measured in orchards treated with pheromone for mating disruption. Exposing males to this aerial concentration of Z8-12:OAc for 15 min, however, had only a small effect on their ability to orientate by flight to virgin calling females in a flight tunnel. Experiments were undertaken to determine if exposure to the main pheromone compound in combination with the two biologically active minor compounds of this species, (E)-8-dodecen-1-yl acetate (E8-12:OAc) and (Z)-8-dodecen-1-ol (Z8-12:OH) would induce greater levels of sensory adaptation and have a greater effect on male sexual behavior. The exposure of male antennae to 0.5 g/m(3) air of one of the three pheromone compounds induced sensory adaptation to this compound and to the other two pheromone compounds demonstrating cross adaptation. Average percentage sensory adaptation to a pheromone compound was similar after 15 min of exposure to 1 ng/m(3) air of Z8-12:OAc, or to 1 ng/m(3) air of a 1:1:1 or 93:6:1 blend of Z8-12:OAc, E8-12:OAc, and Z8-12:OH. The exposure of males to 1 ng/m(3) air of Z8-12:OAc or the two ratios of Z8-12:OAc, E8-12:OAc, and Z8-12:OH for 15 min had no effect on their ability to orientate to a virgin calling female. The implications of these results for the operative mechanisms of sex pheromone-mediated mating disruption of this species are discussed

Effectiveness of plant-derived formulations against the rootknot nematode Meloidogyne incognita (Kofoid et White) Chitw. in a protected tomato crop

The effectiveness of two plant-derived formulations for the control of the root-knot Meloidogyne incognita (Kofoid et White) Chitw. was evaluated in a protected tomato crop in Southern Italy. A neem oil-based formulation and a commercial mixture of aqueous extracts of Quillaja saponaria Molina (80%), Yucca schidigera Roezl (10%) and Tagetes spp. (10%) were tested in comparison with the standard chemical oxamyl and an untreated control. All tested formulations significantly decreased soil nematode population and average root galling compared to the untreated control. However, nematode infestation was found significantly lower in plots treated with oxamyl or neem formulation than in those treated with quillay-based product. Tomato yield did not significantly differ among treatments. Satisfactory yield obtained by quillay-based product appears to be caused by the biostimulating effect of quillay extract on tomato plants

Effectiveness of soil solarization combined with a plant-derived formulation for the control of the root-knot nematode Meloidogyne incognita (Kofoid et White) Chitw. in greenhouse tomato

The effectiveness of soil solarization, alone or in combination with oxamyl or a plant-derived formulation (a mixture of aqueous extracts of Quillaja saponaria Molina , Yucca schidigera Roezl and Tagetes spp., 80, 10 and 10%, respectively), for the control of the root-knot nematode Meloidogyne incognita (Kofoid et White) Chitw. was assessed in a greenhouse trial on tomato at Battipaglia (province of Salerno), Southern Italy. The combination of soil solarization with the plant-derived formulation resulted in a greater nematode suppression than application of single treatments. Combining soil solarization with the plant-derived formulation resulted in tomato yield and fruit size similar to that of the combination of soil solarization with oxamyl. Therefore the combination of soil solarization with plant-derived formulations may represent a sustainable nematode control strategy, as safe for human health and environment

Virological and histological evaluation of intestinal samples in COVID-19 patients

BACKGROUNDSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the pathogen responsible for pandemic coronavirus disease 2019 (COVID-19). It is a highly contagious virus which primarily affects the respiratory tract, nevertheless, the lungs are not the only target organs of the virus. The intestinal tract could represent an additional tropism site for SARS-CoV-2. Several observations have collectively suggested that enteric infections can occur in COVID-19 patients. However, the detection of viral RNA in gastrointestinal (GI) tissue samples has not been adequately investigated and results are conflicting.AIMTo detect the presence of SARS-CoV-2 RNA in intestinal mucosa samples and to evaluate histological features.METHODSThe COVID-19 patients hospitalized at an Italian tertiary hospital from April 2020 to March 2021 were evaluated for enrollment in an observational, monocentric trial. The study population was composed of two groups of adult patients. In the first group (biopsy group, 30 patients), patients were eligible for inclusion if they had mild to moderate disease and if they agreed to have a rectal biopsy; in the second group (surgical specimen group, 6 patients), patients were eligible for inclusion if they underwent intestinal resection during index hospitalization. Fifty-nine intestinal mucosal samples were analyzed.RESULTSViral RNA was not detectable in any of the rectal biopsies performed (0/53). Histological examination showed no enterocyte damage, but slight edema of the lamina propria with mild inflammatory lymphoplasmacytic infiltration. There was no difference in inflammatory infiltrates in patients with and without GI symptoms. SARS-CoV-2 RNA was detected in fecal samples in 6 cases out of 14 cases examined (42.9%). In the surgical specimen group, all patients underwent emergency intestinal resection. Viral RNA was detected in 2 surgical specimens of the 6 examined, both of which were from patients with active neoplastic disease. Histological examination also pointed out abundant macrophages, granulocytes and plasma cells infiltrating the muscular layer and adipose tissue, and focal vasculitis.CONCLUSIONMild-moderate COVID-19 may not be associated with rectal infection by the virus. More comprehensive autopsies or surgical specimens are needed to provide histological evidence of intestinal infection